1. Field of the Invention
This invention relates to an electromagnetic relay used for opening and closing a circuit by operating an armature according to an excitation of a coil, and more particularly to an electromagnetic relay with a built-in resistor for protecting its electromagnetic coil from surge current and a method for manufacturing the electromagnetic relay with the built-in resistor.
2. Description of the Prior Art
Heretofore, there has been used an electromagnetic relay disclosed in U.S. Pat. No. 5,003,274, for example.
The electromagnetic relay is provided with a coil(7), armature(9), connected with a resilient member(10) having a movable contact(11), terminals(5 and 6) having respective fixed contacts(3 and 4), and a resistor R for absorbing surge voltage generated at the time of shutting off the power supply to a coil(7) through terminals(14 and 15), and is so structured as to open a circuit connected between the terminal(5) and a terminal(13) connected with the movable contact(13), and close another circuit connected between the terminal(6) and the terminal(13) according to excitation of the coil(7) by supplying the electric current to the coil(7).
However, in the conventional electromagnetic relay described above, the resistor R is disposed on the terminals(14 and 15) and it is necessary to connect lead wires of the resistor R with both ends of a wound wire(7a) of the coil(7), respectively. Therefore, there is a problem since it is troublesome to connect the resistor with the terminals and the both ends of the wound wire of the coil, and it is difficult to rationalize the manufacturing process of the electromagnetic relay of this kind.